Field of the Invention
The present invention relates to a touch apparatus and a method for determining a position, and more particularly relates to an optical touch apparatus and a method for determining a touch position.
Description of Related Art
Generally, optical touch systems can be classified into two types, a blocking type or a non-blocking type. A blocking optical touch system is based on the principle of signal blocking that a touch object blocks a light signal emitted from a light source (e.g., a string of light emitting diodes or a reflective strip), and optical sensors in the blocking optical touch system sense a shadow having a lower brightness relative to the background of the touch object, such that an occurring position of the touch object and its corresponding touch operation can be determined. On the other hand, a non-blocking optical touch system usually includes an optical touch stylus or the use of a finger which is configured to perform a touch operation on a flat panel display so as to transmit a light signal to the optical sensors. For example, in the non-blocking optical touch system using the optical touch stylus, according to the type of the optical touch stylus, the light signal transmitted from the optical touch stylus to the optical sensors may be actively generated from the internal of the optical touch stylus, or generated by the optical touch stylus reflecting back the light signal transmitted by a light source attached to each optical sensor. Therefore, the optical sensors can determine the occurring position of the touch object and its corresponding touch operation according to the received light signal having a higher brightness relative to the background.
However, in a touch operation surface of the existing optical touch system, the area close to the boundary usually needs a calibration mode to solve a problem that the touch position is not accurately determined in this area. The principle of the calibration mode is mainly about subtracting the actual coordinate from the theoretical coordinate to obtain a difference, and then updating the actual coordinate. From another point of view, a known calibration point is displayed in the touch operation surface, and then the calibration point is clicked to obtain the actual coordinate, the differences obtained from the subtracting calculation are used for updating. However, in some specific application scenarios, this method cannot solve the problem that the touch position is not accurately determined.